The NWS is making a lot of changes for 2018 apparently. Dust Storm Warnings will switch from zone-based to polygon-based warnings.

The NWS will also add a polygon-based Dust Advisory for convective short-fused blowing dust when visibility is less than 1 mile but greater than 1/4 mile. The existing zone-based Blowing Dust Advisory will remain for blowing dust lasting 90 minutes or more.

With the polygon-based Dust Storm Warnings, fewer people will now get alerts on their phones, since Wireless Emergency Alerts works better with the polygon-based warnings than it does with the zone-based warnings.